Mrs. Boyd has a desk full of quarters and nickels. If she has a total of 23 coins with a total face value of $4.55, how many of the coins are nickels?

What properties allow transformation to be used as a problem solving tool

How to do this , and can some one explain

Billie holiday sells children's clothing for sara vaughn's toddler shop. baby blankets sell for $29.99 after a markup rate based on cost of 109%. find the cost and the markup.